JP2007517401A - Method and apparatus for cleaning semiconductor wafers using compressed and / or pressurized foams, bubbles and / or liquids - Google Patents

Abstract

  An apparatus and method for cleaning or chemically treating a semiconductor substrate having a contaminated surface using foam is disclosed. The semiconductor wafer is supported on a rigid support (or layer of foam), and the foam is fed to the opposing surface of the semiconductor wafer while the semiconductor wafer is supported. The foam that contacts the semiconductor wafer is pressurized using a mold to produce a consolidated foam. Next, a relative movement between the mold and the semiconductor wafer is induced, for example, a periodic variation parallel and / or perpendicular to the top surface of the semiconductor wafer, during which the compacted foam contacts the semiconductor wafer and is preferably No contaminants are removed and / or the surface of the semiconductor wafer is chemically treated with foam.

Description

  The present invention relates to the field of semiconductor wafers. More particularly, the present invention relates to a method and apparatus for cleaning semiconductor wafers using compressed and / or pressurized foams, bubbles, and / or liquids.

  Semiconductor cleaning, chemical processing and drying techniques have been well developed over the last 30 years or so. However, the equipment and techniques used to perform these processing steps are extremely expensive. Furthermore, as more advanced lithography and other techniques emerge and demanding performance is required by the final design for semiconductor wafers, the currently available processing techniques will soon be unable to meet the required processing requirements. Conceivable.

  As described above, as semiconductor devices become more complex, semiconductor wafers are increasingly contaminated by multiple sources. This sensitivity is due to the sub-micron feature size and the reduced thickness of the layer deposited on the wafer surface. Currently, the smallest feature size designed in high density integrated circuits is about 0.11 microns. This will soon be reduced to less than 1/10 microns. As feature sizes and films become smaller, the particle size of acceptable contaminants also needs to be controlled to progressively smaller dimensions. In general, the contaminant particle size is about 10 times smaller than the smallest feature size and thus requires control of the contaminant particulate matter better than 1/100 microns (ie better than 10 nm).

  With these physical dimensions, the final product is extremely susceptible to contamination of potential particulate matter both in the environment, ie in the air (from workers and equipment) and in the materials used to process semiconductors. . For example, most of the materials used in cleaning and chemical processing steps such as fluoride, solvents, acids, heavy metals, oxidants, etc. are toxic or dangerous to maintain and dispose of. Similarly, high purity deionized water (DI water) typically used in existing processes is expensive to purchase and process while requiring specialized storage and distribution systems. Chemical treatment and cleaning operations are likewise sources of contamination. Such contamination is due to both surface reactants and physical contaminants, which can be derived from particulate matter delivered to the semiconductor wafer from the chemical treatment and cleaning material itself, regardless of product purity. Can also be transferred from components of the storage and delivery system.

  Furthermore, semiconductor wafers are not manufactured in a continuous process, but are manufactured in a batch process and then stored until the next process, making them more susceptible to this contaminating particulate matter from the environment introduced to the surface. Furthermore, when semiconductor wafers are dried at the end of each batch process so that they can be transported and stored safely, the volatile content of isopropyl alcohol, a solvent commonly used during semiconductor wafer drying, is used. Due to release and other reasons, the use of isopropyl alcohol is problematic.

  In addition, substances other than DI water and isopropyl alcohol may be a route for introducing contaminants into the semiconductor wafer. Contaminants on the semiconductor wafer surface exist as films, individual particles or groups of particles, and absorbing gases. These surface films and particles can be molecular compounds, ionic materials or atomic species. Contaminants in the form of molecular compounds are often concentrated organic vapors from lubricants, greases, photoresists, solvent residues, organic components from deionized water or plastic storage containers, and metal oxides or hydroxides. is there. Contaminants in the form of ionic materials are often cations and anions from inorganic compounds that can be physically adsorbed or chemically bound, such as sodium ions, fluoride ions and chloride ions. be able to. Contaminants in the form of atomic or elemental species should be metals such as copper, aluminum or gold that can be chemically bonded to the semiconductor surface, or silicon particles or metal strips from equipment used in the process Can do.

  Conventional cleaning techniques used to remove these various contaminants include brush scrubbing or megasonic processing. While such techniques currently remove an acceptable amount of contaminants from the semiconductor wafer during processing, such methods are ultimately harsh for increasingly sensitive structures. . The mechanical energy and megasonic energy associated with brush scrubbing damages the devices on the semiconductor wafer, resulting in a corresponding device. A direct contact between a relatively hard surface, such as a brush, and a semiconductor wafer transmits a force greater than that required to remove contaminants. In a cleaning process using only megasonic energy, bubbles and waves are generated, which cause little damage to the substrate, but may limit the particle size range of contaminant particles that can be effectively cleaned. Another known problem with megasonic cleaning is cavitation in which bubbles in the megasonic fluid collapse at the surface of the semiconductor wafer, thereby imparting energy to the surface of the semiconductor wafer. If the bubbles repeatedly collapse at the same part of the surface, this energy can destroy delicate / precise structures on the surface or the surface itself. In addition to these problems, such conventional techniques may not be able to remove sufficient contaminants in the future.

  Another technique that can be used to clean semiconductor wafers involves contacting the semiconductor surface with foam rather than a hard surface (brush scrubbing) or megasonic waves. As shown in FIG. 1, the semiconductor wafer 100 enclosed in the apparatus 102 has bubbles 108 and a foam 106 containing liquid introduced into the surface of the semiconductor wafer 100 through a port 104. When the foam 106 corrodes the surface of the semiconductor wafer 100 and is then drained, particles are scraped off the surface of the semiconductor wafer 100 due to the mass of the bubbles 106. Such a foam process can be improved to perform cleaning to the extent necessary for current or future semiconductor processing.

  The present disclosure relates to an apparatus and method for effectively removing contaminants or processing semiconductor wafers using an improved foam process using pressurized or "jammed" foam. I will provide a.

  In one embodiment, the apparatus includes a support configured to support a semiconductor wafer. The foam manifold is configured to introduce the foam into the semiconductor wafer while the semiconductor wafer is supported by the support. The mold creates pressure on the foam placed on the surface of the semiconductor wafer, producing a consolidated foam. The actuator provides relative movement between the mold and the semiconductor wafer while the compacted foam contacts the surface of the semiconductor wafer and removes unwanted particles from the surface of the semiconductor wafer.

  The mold can include a platen disposed on the foam. The area of the platen can be at least the area of the semiconductor wafer so that pressure is applied to the foam covering the entire surface of the semiconductor wafer. Alternatively, the mold can include a pressure structure that is smaller than the entire surface of the semiconductor wafer such that the pressure is applied to a local area of the foam covering the surface of the semiconductor wafer. Such a pressure structure can be a mandrel or a wheel.

  The foam may contain bubbles whose diameter is at most the maximum linear dimension of the particles on the surface of the semiconductor wafer. Alternatively, the density of the foam (number of bubbles / unit volume) can be sufficient to allow the bubbles to rearrange to the first energy state when pressure is applied rather than bursting, The first energy state is lower than the second energy state of the foam present prior to applying pressure. The apparatus can be configured to provide an additional layer of consolidated foam between the semiconductor wafer and the support.

  The foam can include liquids and bubbles, which include chemicals that chemically process the semiconductor wafer. The liquid can be configured to etch a semiconductor wafer or a layer disposed on the semiconductor wafer and can include a cleaning agent suitable for cleaning the semiconductor wafer, or HCl, ammonium hydroxide, SC1 (standard detergent 1-ammonium hydroxide-hydrogen peroxide-water mixture, typically 0.25: 1: 5), SC2 (standard detergent 2-hydrochloric acid-hydrogen peroxide-water mixture, typically Can include 1: 1: 5), and at least one of HF. The foam may include bubbles that contain a reactive gas.

  The actuator can be configured to move the mold while maintaining the position of the semiconductor wafer. The actuator can also be configured to periodically cycle the mold so that the distance between the mold and the surface of the semiconductor wafer varies, so that the mold periodically varies laterally on the surface of the semiconductor wafer. Can be configured such that the mold can be cycled in a transverse direction in a plurality of non-parallel directions, the mold can be configured to rotate, or the mold can be configured to be a plurality of non-parallel It can also be configured to move in the direction.

The actuator can be configured to move the semiconductor wafer while maintaining the position of the mold. The actuator can be configured to periodically vary the semiconductor wafer in the lateral direction, and can be configured to periodically vary the semiconductor wafer in the lateral direction in a plurality of non-parallel directions so as to rotate the semiconductor wafer. Alternatively, the semiconductor wafer can be configured to move in a plurality of non-parallel directions.
The apparatus can further include a container containing a support, a foam manifold, a mold, and an actuator, and can also include a channel through which liquid resulting from the collapse of the compacted foam is removed from the surface of the semiconductor wafer. .

The apparatus includes a plurality of manifolds configured to introduce foam into the semiconductor wafer, one or more manifolds configured to dry the semiconductor wafer after exposing the semiconductor wafer to the compacted foam, foam One or more manifolds configured to cause foam to be fed to the foam manifold after generating or one or more manifolds configured to distribute the foam to the foam manifold Can further be included.
The following drawings and detailed description of preferred embodiments will more clearly show these and other objects and advantages of the present invention.

  There are several reasons for using foam when processing semiconductor wafers, but above all the ability to process the surface of semiconductor wafers without the use of large physical forces that are likely to destroy precise structures. It is advantageous at having. In addition, foam-based cleaning systems can remove more particles that are produced, unlike other systems where the number of particles can increase in successive processing steps.

  The process of creating a foam is relatively simple, i.e., by mixing a gas with a liquid, a suitable liquid is converted into a foam. A suitable liquid is one that can produce the desired foam, and the liquid phase of the foam is substantially the same as the original liquid used to produce the foam, so that the desired chemical treatment is applied to the semiconductor wafer. provide. The foam can be produced by mixing an insoluble gas such as air or by depressurizing a solution containing the soluble gas in the liquid. In either case, energy is applied to the mixture to form a foam.

  The foam is metastable when formed. This means that the foam collapses immediately after production, which essentially regenerates the gas and the original liquid. This decay process is called discharge. The discharge speed is called discharge time and varies depending on the foam. For example, the discharge time of a foam having a shaving cream consistency can be several hours, and the discharge time of a foam having a shampoo consistency can be several minutes or less. The drain time can be controlled by changing the type of liquid that makes up the foam and the density of the foam, which is desirable to aid in the processing of the semiconductor wafer, for example.

  The foam can be produced or stored in a pressurized environment. When discharged from the storage facility from this pressurized environment, for example through a manifold, the volume of the foam expands. When applied to a semiconductor wafer through a manifold, such foam reduces the volume of reactants and solvents in the liquid that contacts the semiconductor wafer. However, the foam also reduces exposure of the semiconductor wafer to contaminants in the conduit where the foam is transferred to the semiconductor wafer because less material passes through the conduit. The foam also exhibits thixotropic flow characteristics and therefore flows best under shear forces. Some foams, which have similar properties to shaving creams, spread easily under high shear forces, but remain substantially stationary when the shear force is removed. Under low shear forces, the foam generally acts like an elastic solid. In addition, since the surface tension is generated by the walls of the bubbles in the foam, the use of liquids with low surface tension and low viscosity can penetrate typical structures fabricated on semiconductor wafers such as vias and trenches. it can.

  Both the liquid and gas types that form the foam, and environmental factors present during foam production, such as temperature and pressure, can be adjusted to control the foam composition. For example, the use of high purity liquids, such as water or chemicals used for other types of chemical processing (eg, etching), increases the effectiveness of foaming because there is little contaminant that prevents foaming. Also, when forming the foam, an auxiliary agent that reduces surface tension, such as soap, detergent, isopropyl alcohol, nitrous oxide, isobutane, or carbon dioxide, may be added to the liquid. In addition, since the surface tension is reduced, foaming is better at higher temperatures, and the foaming operation can be optimized by adjusting the temperature of the liquid used. In one embodiment, a suitable foam discharge time can be less than 1-2 minutes. Therefore, it is possible to use a foam that discharges at a relatively high speed. In fact, it may be desirable to use a somewhat faster discharge foam in that few, if any, such additional foams do not require additional means to be removed. .

  As shown in FIG. 1, the proposed technique for cleaning a semiconductor wafer moves the foam over the surface of the substrate by dipping the semiconductor wafer into the foam or by erosion and drainage. Make it possible. When the foam is depressurized during discharge, energy is transferred to the surface of the semiconductor wafer as the bubbles collapse. However, this technique releases too little energy when the foam bubbles collapse and remove contamination from the surface of the semiconductor wafer.

  However, in the embodiment of the present invention shown in FIG. 2, the semiconductor wafer is cleaned or otherwise processed using so-called “consolidated” foams. In this embodiment, the semiconductor wafer 10 is placed between two platens 12, 14 and the foam 16 is placed on one or both sides of the semiconductor wafer 10 (shown on both sides in the figure). Any of several types of semiconductor wafers, such as silicon or other Group IV substrates or Group III-V or II-VI compound semiconductor substrates, may also be used with embodiments of the present invention. Can be processed.

  In general, the bottom platen 14 provides a support on which the semiconductor wafer 10 is placed, regardless of whether foam is present. The foam 16 is disposed over substantially the entire surface of the existing semiconductor wafer 10. The foam can be applied and spread by any suitable means such as one or more manifolds. As shown here, uniform pressure is applied to the foam 16 through the top platen 12 and possibly the bottom platen 14. At this pressure, a consolidated foam 16 that transfers energy to the semiconductor wafer 10 is generated primarily by rearranging the bubbles in the foam 16 rather than by the collapse of the bubbles. The way this is believed to occur is that when the pressure increases, the foam first enters a metastable high energy state where rearrangement does not occur, then the foam relaxes at a critical stress level, leading to bubble collapse. Regardless, the energy is released by the rearrangement of the bubbles.

  When the foam becomes a consolidated foam, the foam layer becomes progressively thinner and eventually reaches a minimum thickness. The minimum thickness depends on the liquid and gas components used, but typically the semiconductor surface can be treated with bubbles of diameter 10-50 μm, so the layer thickness can be less than the bubble diameter There is no sex. On the other hand, if the density of the foam is too small, the bubbles are separated by gravity and burst before the bubbles reach the interface and can be rearranged. Further, since small bubbles are more stable than large bubbles, providing small bubbles to the foam can improve processing efficiency by increasing the number of bubbles rearranged at the interface.

  In general, the upper surface of the semiconductor wafer 10 includes a pattern structure that requires cleaning or other chemical treatment. Thus, if no processing is required on the lower surface of the semiconductor wafer 10, the bottom platen 14 can be removed and replaced with a fixed support structure that simply supports the semiconductor wafer and does not apply pressure. In this case, the foam 16 may not be disposed on the lower surface of the semiconductor wafer 10. The support surface may be stationary or mobile, such as a conveyor belt. On the other hand, the platen can be formed using any suitable material that is strong enough to withstand the energy transferred to the platen by repeated exposure to the collapsing bubbles.

  A typical rearrangement is shown in FIGS. 2A and 2B. In FIG. 2A, the foam 16 is placed on the surface 10 of the semiconductor wafer without applying pressure. FIG. 2B shows the rearrangement of the foam 16 when pressure is applied (a platen or other pressurized structure is not shown in this view). As shown, energy is released as the foam 16 progresses from a high energy disordered state to a low energy ordered state. Since the bubbles shown in the figure have a spherical nature, the foam tends to rearrange into a hexagonal close-packed structure.

  At the end of the processing step using the foam, the foam can be removed (or rinsed away) with DI water, for example, it must be chemically rinsed with additional liquid before rinsing with DI water. In some cases. The remaining DI water can then be removed in a controlled manner by adding nitrogen or other inert gas to the semiconductor wafer surface. In an uncontrolled drying process, i.e. where the semiconductor wafer can be dried without removing the foam, contaminants removed by the foam or undesirable residues and chemicals of the foam itself may remain. . Another process can then be performed, and if necessary, new foam can be introduced later onto the surface of the semiconductor wafer. The new foam can have the same or different chemistry as the original foam, if desired. Since the foam contains contaminants and reaction products with the surface of the semiconductor wafer, it is generally not reused after use.

  The platen shown in FIG. 2 covers the entire semiconductor wafer and thus applies a uniform pressure to the foam, but the pressure need not be applied uniformly to the foam. As illustrated in the embodiment shown in FIG. 4, the semiconductor wafer 20 and foam 26 are disposed between one or more molds 22, 24. In the embodiment of FIG. 4, pressure is applied to the foam 26 through molds 22, 24 only over a small portion of the surface of the semiconductor wafer 20. Unlike the platen in the embodiment of FIG. 2, the molds 22, 24 of this embodiment do not substantially cover the entire surface of the opposing semiconductor wafer 20. Similar to the previous embodiment, only one mold can be applied to the semiconductor wafer 20. This single mold, such as a single platen, is placed over the upper surface of the semiconductor wafer 20 where there are patterns that require cleaning or other processing. Although not shown in this embodiment, a plurality of molds (platens, rollers, etc.) can be arranged on one surface of the semiconductor wafer 20.

  The foam 26 in the embodiment of FIG. 4 may or may not be disposed over the entire surface of the semiconductor wafer 20. If not entirely covered, the foam 26 can be placed over only a portion of the semiconductor wafer 20 that requires cleaning or processing. The molds 22, 24 can move across the surface of the semiconductor wafer 20 at least once or back and forth. If multiple molds exist over either the same surface or opposing surfaces of the semiconductor wafer, the molds can be moved across the surface of the semiconductor wafer, either simultaneously or separately as desired. As shown, the molds 22, 24 can be mandrels, rollers, wheels, or any other pressure structure that covers only a portion of the semiconductor wafer 20. Thus, the mold can be flat or curved.

  It should also be noted that a curved mold can be easier to implement than a flat mold. Furthermore, the time required to clean or treat the semiconductor surface can affect whether the mold is flat. In this case, if only a short time is required, a thin line that contacts at high pressure can be used, and the mold can therefore roll along the foam. Conversely, if a long time is required, a flat surface is probably better. Furthermore, if the discharge time is relatively fast, any reactant contained in the foam will be added to the semiconductor wafer as a liquid.

FIG. 5 illustrates one manner in which the foam 38 is formed and moved. In this figure, only one pressure structure 32 (shown as a platen) is shown, but it is clear that multiple pressure structures can be used. As shown, the platen 32 has a plurality of holes 34, 36 extending through the platen 32. Through at least one of these holes 34 (foam manifold), a foam 38 is introduced into the surface of the semiconductor 30 and through at least another one of these holes 36, the foam 38 is introduced into the semiconductor surface 30. Spill from. Foam 38 can be deposited from inlet hole 34 toward outlet hole 36 by evacuation or by using a non-reactive gas such as nitrogen as shown. The foam on the surface of the semiconductor wafer 30 can be pressed toward the outlet hole 36 by nitrogen. In addition to causing rearrangement due to the applied pressure, the movement of the foam 38 causes the semiconductor surface 30 to be cleaned or treated. A vacuum or other pressure differential is applied to the outlet hole 36 to cause the foam 34 or vacuum foam liquid to flow out of the semiconductor surface 30. The holes 34, 36 can be positioned at any point along the platen 32, but are preferably arranged such that the foam is supplied over the entire surface of the semiconductor surface 30. Liquid is supplied through inlet hole 34 and aerated with gas (denoted O ₃ ) to form foam 38.

  FIG. 6 shows an embodiment in which foam is present on both sides of the semiconductor wafer (although the foam on the upper surface and pressure structure is not shown). After the foam 46 is introduced into the platen 42 (or other support), the semiconductor wafer 40 is placed on the foam 46. Next, the semiconductor wafer 40 is placed on three or more stands 44 of the support 42. The stand 44 is identical in size and shape and extends from the support 42 through the foam 46. Once the semiconductor wafer 40 is securely placed on the stand 44, the stand 44 can be retracted into the support 42 so that the semiconductor wafer 40 rests on the foam 46. Before or after the stand is retracted, an additional layer of foam can be applied to the surface of the opposing semiconductor wafer. After injecting the foam, the semiconductor wafer 40 can then be processed.

  FIG. 7 shows another embodiment of the present invention. In this embodiment, the foam 56 can be placed on both opposing surfaces of the semiconductor wafer 50 and multiple pressure mechanisms can be used, but for simplicity, the foam 56 is a semiconductor wafer. A platen 52 that is placed on only one surface of 50 and to which pressure is applied is shown to be placed on the foam 56. As mentioned above, the foam flows best under shear. Accordingly, the shear force can be applied using the pressure, and at the same time, the effectiveness of the foam 56 on the semiconductor wafer 50 can be increased by moving the platen 52 or the platen 52 and the semiconductor wafer 50.

  As shown, the semiconductor wafer 50 and the platen 52 can translate in one or more directions, such as laterally (ie, in the semiconductor plane) or perpendicular to each other. Thereby, it can be said that the foam 56 can be compressed and expanded by vertical movement, that is, the semiconductor wafer 50 and the platen 52 can move toward each other or away from each other. Alternatively, the foam 56 can be sheared by lateral movement, ie, the semiconductor wafer 50 and platen 52 can be moved to adjust the overlap between the two. This movement is repeated, ie, the semiconductor wafer 50 and platen 52 are periodically cycled in one or more directions to induce more efficient processing. Similarly, the semiconductor wafer 50 and / or the platen 52 can be rotated to cause movement rather than adjusting the two positions relative to each other. However, when rotating, different linear velocities are generated at different radii, so that a better processing result can be obtained with periodic variation. In summary, the mold can be moved while keeping the position of the semiconductor wafer constant, the semiconductor wafer can be moved while keeping the position of the mold constant, and both the semiconductor wafer and the mold are moved simultaneously or sequentially. You can also

  In the above embodiment, only a single wafer is placed between the mold and the support (or between the molds). In another embodiment, a plurality of semiconductor wafers can be placed between or between the mold and the support, and the semiconductor wafer can sandwich the foam layer. However, in this case, it may be difficult to position the semiconductor wafers and, if accompanied by movement, make the movement between the semiconductor wafers uniform (and thus obtain uniform results).

  As discussed above, the foam is composed of bubbles filled with liquid and gas. The foam can be a delivery vehicle for other materials, and at the same time rearrangement can make the foam itself useful. In addition to simply applying energy to the surface of the semiconductor wafer to clean it, other chemical properties can be present in the foam. Foams can be formed from process fluids used in conventional semiconductor processes to facilitate the process. Examples of such fluids include HCl to exfoliate and undercut oxides present on the surface of a semiconductor wafer to remove particles embedded in oxides, nitric acid, ammonium hydroxide and hydrogen peroxide, Ammonium hydroxide, SC1, SC2, HF are included. Other fluids that help clean the surface can also be used. For example, when using a high ph fluid on a negatively charged semiconductor surface, particles that are positively charged and adhere to the surface will become negatively charged when removed by the foam, thereby reattaching the particles. Is blocked.

  Not only can liquids with different chemistry be used to assist in processing semiconductor wafers, but also foams are formed using reactive gases rather than inert gases such as nitrogen, argon, air, or carbon dioxide. You can also. Such an arrangement provides a useful delivery system for delivering gas to the surface of the semiconductor.

  FIG. 8 shows one embodiment of an apparatus that uses a foam treatment process. The semiconductor wafer 60 is supported by the support body 62. The storage system 64 can have one or more chambers through which the semiconductor wafer 60 passes (only one is shown in the figure). There are multiple manifolds. For example, as shown in FIG. 4, at least one manifold produces foam. The foam 66 is introduced or supplied to the semiconductor wafer 60 by at least one manifold 67. Gas and liquid supply lines (with appropriate valves) supply the manifold with raw materials for producing foam. After adding foam 66 and allowing mold 65 to act on the foam, semiconductor wafer 60 is rinsed in DI water by one or more manifolds 68. After rinsing the semiconductor wafer 60, the semiconductor wafer 60 is dried by one or more manifolds.

  Of course, different foams can be dispensed by the same or different manifolds, which are then pressurized to add the consolidated foam to the semiconductor. Moreover, the drying process using a foam can also be used. In such a process, the desired foam can be produced by the carbon dioxide gas / DI water mixture. Many other configurations for such an apparatus are possible, as is well known in the semiconductor processing field. For example, cleaning, chemical treatment and drying can be performed in the same or different chambers. Typically, the cleaning and chemical treatment steps are performed sequentially without any intermediate drying steps, and the drying steps are only performed at the final stage where the semiconductor wafer is to be removed from the system. However, cleaning and chemical treatment can also be performed in the same chamber alternating with drying.

  While this invention has been described with reference to specific embodiments, this description is illustrative of the invention and is not to be construed as limiting the invention. Various modifications and applications can occur to those skilled in the art without departing from the true spirit and scope of the invention as defined in the appended claims.

It is a figure which shows a well-known foam apparatus. It is a figure which shows the washing | cleaning apparatus by the 1st aspect of this invention. FIG. 4 shows bubbles prior to rearrangement in one aspect of the invention. FIG. 6 shows bubbles after rearrangement in one aspect of the invention. It is a figure which shows the washing | cleaning apparatus by the 2nd aspect of this invention. It is a figure which shows the washing | cleaning apparatus by the 3rd aspect of this invention. It is a figure which shows the washing | cleaning apparatus by the 4th aspect of this invention. It is a figure which shows the washing | cleaning apparatus by the 5th aspect of this invention. It is a figure which shows the washing | cleaning apparatus by the 6th aspect of this invention.

Claims (20)

An apparatus for processing a semiconductor wafer, the apparatus comprising:
A support configured to support the semiconductor wafer;
A foam manifold configured to introduce foam to a surface of the semiconductor wafer while the semiconductor wafer is supported by the support;
A mold for generating a consolidated foam by applying pressure to the foam disposed on a surface of the semiconductor wafer;
An actuator that causes relative movement between the mold and the semiconductor wafer to remove unwanted particles from the surface of the semiconductor wafer while the consolidated foam is in contact with the surface of the semiconductor wafer;
The apparatus characterized by including.   The mold includes a platen disposed on the foam, and the platen has at least an area of the semiconductor wafer, and the pressure is applied to the foam covering the entire surface of the semiconductor wafer. The apparatus according to claim 1, wherein:   The mold includes a pressure structure that is smaller than an entire surface of the semiconductor wafer, and the pressure is applied to the foam in a localized area covering the surface of the semiconductor wafer. The device described in 1.   The actuator periodically fluctuates the mold or the semiconductor wafer in a vertical direction so that a distance between the mold and the surface of the semiconductor wafer changes, or moves the mold or the semiconductor wafer in a plurality of non-parallel directions. The apparatus according to claim 1, wherein the apparatus is configured to cycle in a lateral direction or to rotate the mold or the semiconductor wafer.   The apparatus of claim 1, wherein the apparatus is configured to provide an additional layer of consolidated foam between the semiconductor wafer and the support.   The apparatus of claim 1, wherein the liquid obtained by the collapse of the compacted foam further comprises a channel that is removed from the surface of the semiconductor wafer.   The apparatus according to claim 1, wherein the foam includes a liquid and bubbles, and the liquid includes a chemical substance that performs chemical processing on the semiconductor wafer.   8. The apparatus of claim 7, wherein the liquid is configured to etch the semiconductor wafer or a layer disposed on the semiconductor wafer.   8. The apparatus of claim 7, wherein the liquid includes a cleaning agent suitable for cleaning the semiconductor wafer.   The apparatus according to claim 1, wherein the foam includes bubbles containing a reactive gas.   The foam was introduced into the semiconductor wafer, deionized water (DIW) was added to the semiconductor wafer after the semiconductor wafer was exposed to the consolidated foam, and the semiconductor wafer was exposed to the consolidated foam. A chemical treatment agent and DIW are added to the semiconductor wafer later, an inert gas is added to the semiconductor wafer after the semiconductor wafer is exposed to the consolidated foam, and the foam is formed after the foam is formed. The apparatus of claim 1, further comprising a manifold configured to supply a foam manifold and / or distribute the foam to the foam manifold. A method of processing a semiconductor wafer, the method comprising:
Supporting the semiconductor wafer;
Supplying foam on a first surface of the semiconductor wafer while supporting the semiconductor wafer;
Applying pressure to the foam disposed on the semiconductor wafer using a mold to produce a consolidated foam;
Creating a relative movement between the mold and the semiconductor wafer while the consolidated foam is in contact with the semiconductor wafer;
Including methods.   The method of claim 12, further comprising applying pressure to the foam covering the entire first surface of the semiconductor wafer.   The method of claim 12, further comprising applying pressure only to the foam in a localized area covering the semiconductor wafer.   The method further comprises the step of periodically changing the mold or the semiconductor wafer to change the distance between the mold and the surface of the semiconductor wafer or the amount of overlap between the mold and the surface of the semiconductor wafer. The method described in 1.   The method of claim 12, further comprising providing an additional layer of consolidated foam on the second surface of the semiconductor wafer.   The method of claim 12, further comprising chemically treating the semiconductor wafer with the foam liquid.   The method of claim 12, further comprising producing a foam, wherein the foam bubbles comprise a reactive gas.   The method of claim 12, further comprising drying the semiconductor wafer after the semiconductor wafer is exposed to the consolidated foam.   Adding deionized water (DIW) to the semiconductor wafer after the semiconductor wafer is exposed to the compacted foam, and DIW and chemical treatment agent are applied to the semiconductor wafer after the semiconductor wafer is exposed to the compacted foam; The method of claim 12, further comprising adding to the semiconductor wafer and / or adding an inert gas to the semiconductor wafer after the semiconductor wafer is exposed to the consolidated foam.

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